[PATCH v2 0/9] Touch Bar support for T2 Macs

[PATCH v2 0/9] Touch Bar support for T2 Macs

[Aditya Garg]

Hi Maintainers

The Touch Bars found on x86 Macs support two USB configurations: one
where the device presents itself as a HID keyboard and can display
predefined sets of keys, and one where the operating system has full
control over what is displayed.

This patch series adds support for both the configurations.

The hid-appletb-bl driver adds support for the backlight of the Touch Bar.
This enables the user to control the brightness of the Touch Bar from
userspace. The Touch Bar supports 3 modes here: Max brightness, Dim and Off.
So, daemons, used to manage Touch Bar can easily manage these modes by writing
to /sys/class/backlight/appletb_backlight/brightness. It is needed by both the
configurations of the Touch Bar.

The hid-appletb-kbd adds support for the first (predefined keys) configuration.
There are 4 modes here: Esc key only, Fn mode, Media keys and No keys.
Mode can be changed by writing to /sys/bus/hid/drivers/hid-appletb-kbd/<dev>/mode
This configuration is what Windows uses with the official Apple Bootcamp drivers.

Rest patches support the second configuration, where the OS has full control
on what's displayed on the Touch Bar. It is achieved by the patching the
hid-multitouch driver to add support for touch feedback from the Touch Bar
and the appletbdrm driver, that displays what we want to on the Touch Bar.
This configuration is what macOS uses.

The appletbdrm driver is based on the similar driver made for Windows by
imbushuo [1].

Currently, a daemon named tiny-dfr [2] is being used to display function keys
and media controls using the second configuration for both Apple Silicon and
T2 Macs.

A daemon for the first configuration is being developed, but that's a userspace
thing.

[1]: https://github.com/imbushuo/DFRDisplayKm
[2]: https://github.com/WhatAmISupposedToPutHere/tiny-dfr

v2:
  1. Cleaned up some code in the hid-appletb-kbd driver.
  2. Fixed wrong subject in drm/format-helper patch.
  3. Fixed Co-developed-by wrongly added to hid-multitouch patch.

Kerem Karabay (9):
  HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars
  HID: hid-appletb-kbd: add driver for the keyboard mode of Apple Touch
    Bars
  HID: multitouch: support getting the contact ID from
    HID_DG_TRANSDUCER_INDEX fields
  HID: multitouch: support getting the tip state from HID_DG_TOUCH
    fields
  HID: multitouch: take cls->maxcontacts into account for devices
    without a HID_DG_CONTACTMAX field too
  HID: multitouch: allow specifying if a device is direct in a class
  HID: multitouch: add device ID for Apple Touch Bars
  drm/format-helper: Add conversion from XRGB8888 to BGR888
  drm/tiny: add driver for Apple Touch Bars in x86 Macs

 .../ABI/testing/sysfs-driver-hid-appletb-kbd  |  13 +
 MAINTAINERS                                   |  12 +
 drivers/gpu/drm/drm_format_helper.c           |  54 ++
 .../gpu/drm/tests/drm_format_helper_test.c    |  81 +++
 drivers/gpu/drm/tiny/Kconfig                  |  12 +
 drivers/gpu/drm/tiny/Makefile                 |   1 +
 drivers/gpu/drm/tiny/appletbdrm.c             | 624 ++++++++++++++++++
 drivers/hid/Kconfig                           |  22 +
 drivers/hid/Makefile                          |   2 +
 drivers/hid/hid-appletb-bl.c                  | 206 ++++++
 drivers/hid/hid-appletb-kbd.c                 | 303 +++++++++
 drivers/hid/hid-multitouch.c                  |  60 +-
 drivers/hid/hid-quirks.c                      |   8 +-
 include/drm/drm_format_helper.h               |   3 +
 14 files changed, 1385 insertions(+), 16 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd
 create mode 100644 drivers/gpu/drm/tiny/appletbdrm.c
 create mode 100644 drivers/hid/hid-appletb-bl.c
 create mode 100644 drivers/hid/hid-appletb-kbd.c

-- 
2.39.3 (Apple Git-146)

[PATCH v2 1/9] HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars

[Aditya Garg]

From: Kerem Karabay <kekrby@gmail.com>

This commit adds a driver for the backlight of Apple Touch Bars on x86
Macs. Note that currently only T2 Macs are supported.

This driver is based on previous work done by Ronald Tschalär
<ronald@innovation.ch>.

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Co-developed-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
 MAINTAINERS                  |   6 +
 drivers/hid/Kconfig          |  10 ++
 drivers/hid/Makefile         |   1 +
 drivers/hid/hid-appletb-bl.c | 206 +++++++++++++++++++++++++++++++++++
 drivers/hid/hid-quirks.c     |   4 +-
 5 files changed, 226 insertions(+), 1 deletion(-)
 create mode 100644 drivers/hid/hid-appletb-bl.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 8766f3e5e..ac27f41d4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9931,6 +9931,12 @@ F:	include/linux/pm.h
 F:	include/linux/suspend.h
 F:	kernel/power/
 
+HID APPLE TOUCH BAR DRIVERS
+M:	Kerem Karabay <kekrby@gmail.com>
+L:	linux-input@vger.kernel.org
+S:	Maintained
+F:	drivers/hid/hid-appletb-*
+
 HID CORE LAYER
 M:	Jiri Kosina <jikos@kernel.org>
 M:	Benjamin Tissoires <bentiss@kernel.org>
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 08446c89e..4988c1fb2 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -148,6 +148,16 @@ config HID_APPLEIR
 
 	Say Y here if you want support for Apple infrared remote control.
 
+config HID_APPLETB_BL
+	tristate "Apple Touch Bar Backlight"
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want support for the backlight of Touch Bars on x86
+	  MacBook Pros.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hid-appletb-bl.
+
 config HID_ASUS
 	tristate "Asus"
 	depends on USB_HID
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index e40f1ddeb..1d825a474 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_HID_ALPS)		+= hid-alps.o
 obj-$(CONFIG_HID_ACRUX)		+= hid-axff.o
 obj-$(CONFIG_HID_APPLE)		+= hid-apple.o
 obj-$(CONFIG_HID_APPLEIR)	+= hid-appleir.o
+obj-$(CONFIG_HID_APPLETB_BL)	+= hid-appletb-bl.o
 obj-$(CONFIG_HID_CREATIVE_SB0540)	+= hid-creative-sb0540.o
 obj-$(CONFIG_HID_ASUS)		+= hid-asus.o
 obj-$(CONFIG_HID_AUREAL)	+= hid-aureal.o
diff --git a/drivers/hid/hid-appletb-bl.c b/drivers/hid/hid-appletb-bl.c
new file mode 100644
index 000000000..00bbe45df
--- /dev/null
+++ b/drivers/hid/hid-appletb-bl.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Apple Touch Bar Backlight Driver
+ *
+ * Copyright (c) 2017-2018 Ronald Tschalär
+ * Copyright (c) 2022-2023 Kerem Karabay <kekrby@gmail.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/hid.h>
+#include <linux/backlight.h>
+
+#include "hid-ids.h"
+
+#define APPLETB_BL_ON			1
+#define APPLETB_BL_DIM			3
+#define APPLETB_BL_OFF			4
+
+#define HID_UP_APPLEVENDOR_TB_BL	0xff120000
+
+#define HID_VD_APPLE_TB_BRIGHTNESS	0xff120001
+#define HID_USAGE_AUX1			0xff120020
+#define HID_USAGE_BRIGHTNESS		0xff120021
+
+static int appletb_bl_def_brightness = 2;
+module_param_named(brightness, appletb_bl_def_brightness, int, 0444);
+MODULE_PARM_DESC(brightness, "Default brightness:\n"
+			 "    0 - Touchbar is off\n"
+			 "    1 - Dim brightness\n"
+			 "    [2] - Full brightness");
+
+struct appletb_bl {
+	struct hid_field *aux1_field, *brightness_field;
+	struct backlight_device *bdev;
+
+	bool full_on;
+};
+
+const u8 appletb_bl_brightness_map[] = {
+	APPLETB_BL_OFF,
+	APPLETB_BL_DIM,
+	APPLETB_BL_ON
+};
+
+static int appletb_bl_set_brightness(struct appletb_bl *bl, u8 brightness)
+{
+	struct hid_report *report = bl->brightness_field->report;
+	struct hid_device *hdev = report->device;
+	int ret;
+
+	ret = hid_set_field(bl->aux1_field, 0, 1);
+	if (ret) {
+		hid_err(hdev, "Failed to set auxiliary field (%pe)\n", ERR_PTR(ret));
+		return ret;
+	}
+
+	ret = hid_set_field(bl->brightness_field, 0, brightness);
+	if (ret) {
+		hid_err(hdev, "Failed to set brightness field (%pe)\n", ERR_PTR(ret));
+		return ret;
+	}
+
+	if (!bl->full_on) {
+		ret = hid_hw_power(hdev, PM_HINT_FULLON);
+		if (ret < 0) {
+			hid_err(hdev, "Device didn't power on (%pe)\n", ERR_PTR(ret));
+			return ret;
+		}
+
+		bl->full_on = true;
+	}
+
+	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
+
+	if (brightness == APPLETB_BL_OFF) {
+		hid_hw_power(hdev, PM_HINT_NORMAL);
+		bl->full_on = false;
+	}
+
+	return 0;
+}
+
+static int appletb_bl_update_status(struct backlight_device *bdev)
+{
+	struct appletb_bl *bl = bl_get_data(bdev);
+	u16 brightness;
+
+	if (bdev->props.state & BL_CORE_SUSPENDED)
+		brightness = 0;
+	else
+		brightness = backlight_get_brightness(bdev);
+
+	return appletb_bl_set_brightness(bl, appletb_bl_brightness_map[brightness]);
+}
+
+static const struct backlight_ops appletb_bl_backlight_ops = {
+	.options = BL_CORE_SUSPENDRESUME,
+	.update_status = appletb_bl_update_status,
+};
+
+static int appletb_bl_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	struct hid_field *aux1_field, *brightness_field;
+	struct backlight_properties bl_props = { 0 };
+	struct device *dev = &hdev->dev;
+	struct appletb_bl *bl;
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID parse failed\n");
+
+	aux1_field = hid_find_field(hdev, HID_FEATURE_REPORT,
+				    HID_VD_APPLE_TB_BRIGHTNESS, HID_USAGE_AUX1);
+
+	brightness_field = hid_find_field(hdev, HID_FEATURE_REPORT,
+					  HID_VD_APPLE_TB_BRIGHTNESS, HID_USAGE_BRIGHTNESS);
+
+	if (!aux1_field || !brightness_field)
+		return -ENODEV;
+
+	if (aux1_field->report != brightness_field->report)
+		return dev_err_probe(dev, -ENODEV, "Encountered unexpected report structure\n");
+
+	bl = devm_kzalloc(dev, sizeof(*bl), GFP_KERNEL);
+	if (!bl)
+		return -ENOMEM;
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DRIVER);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID hardware start failed\n");
+
+	ret = hid_hw_open(hdev);
+	if (ret) {
+		dev_err_probe(dev, ret, "HID hardware open failed\n");
+		goto stop_hw;
+	}
+
+	bl->aux1_field = aux1_field;
+	bl->brightness_field = brightness_field;
+
+	if (appletb_bl_def_brightness == 0)
+		ret = appletb_bl_set_brightness(bl, APPLETB_BL_OFF);
+	else if (appletb_bl_def_brightness == 1)
+		ret = appletb_bl_set_brightness(bl, APPLETB_BL_DIM);
+	else
+		ret = appletb_bl_set_brightness(bl, APPLETB_BL_ON);
+
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to set touch bar brightness to off\n");
+		goto close_hw;
+	}
+
+	bl_props.type = BACKLIGHT_RAW;
+	bl_props.max_brightness = ARRAY_SIZE(appletb_bl_brightness_map) - 1;
+
+	bl->bdev = devm_backlight_device_register(dev, "appletb_backlight", dev, bl,
+						  &appletb_bl_backlight_ops, &bl_props);
+	if (IS_ERR(bl->bdev)) {
+		ret = PTR_ERR(bl->bdev);
+		dev_err_probe(dev, ret, "Failed to register backlight device\n");
+		goto close_hw;
+	}
+
+	hid_set_drvdata(hdev, bl);
+
+	return 0;
+
+close_hw:
+	hid_hw_close(hdev);
+stop_hw:
+	hid_hw_stop(hdev);
+
+	return ret;
+}
+
+static void appletb_bl_remove(struct hid_device *hdev)
+{
+	struct appletb_bl *bl = hid_get_drvdata(hdev);
+
+	appletb_bl_set_brightness(bl, APPLETB_BL_OFF);
+
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
+static const struct hid_device_id appletb_bl_hid_ids[] = {
+	/* MacBook Pro's 2018, 2019, with T2 chip: iBridge DFR Brightness */
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, appletb_bl_hid_ids);
+
+static struct hid_driver appletb_bl_hid_driver = {
+	.name = "hid-appletb-bl",
+	.id_table = appletb_bl_hid_ids,
+	.probe = appletb_bl_probe,
+	.remove = appletb_bl_remove,
+};
+module_hid_driver(appletb_bl_hid_driver);
+
+MODULE_AUTHOR("Ronald Tschalär");
+MODULE_AUTHOR("Kerem Karabay <kekrby@gmail.com>");
+MODULE_DESCRIPTION("MacBookPro Touch Bar Backlight Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c
index e0bbf0c63..818d41a35 100644
--- a/drivers/hid/hid-quirks.c
+++ b/drivers/hid/hid-quirks.c
@@ -328,7 +328,6 @@ static const struct hid_device_id hid_have_special_driver[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_GEYSER1_TP_ONLY) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_2021) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_FINGERPRINT_2021) },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
 #endif
 #if IS_ENABLED(CONFIG_HID_APPLEIR)
@@ -338,6 +337,9 @@ static const struct hid_device_id hid_have_special_driver[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IRCONTROL4) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IRCONTROL5) },
 #endif
+#if IS_ENABLED(CONFIG_HID_APPLETB_BL)
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
+#endif
 #if IS_ENABLED(CONFIG_HID_ASUS)
 	{ HID_I2C_DEVICE(USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_I2C_KEYBOARD) },
 	{ HID_I2C_DEVICE(USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_I2C_TOUCHPAD) },
-- 
2.39.3 (Apple Git-146)

[PATCH v2 2/9] HID: hid-appletb-kbd: add driver for the keyboard mode of Apple Touch Bars

[Aditya Garg]

From: Kerem Karabay <kekrby@gmail.com>

The Touch Bars found on x86 Macs support two USB configurations: one
where the device presents itself as a HID keyboard and can display
predefined sets of keys, and one where the operating system has full
control over what is displayed. This commit adds a driver for the
display functionality of the first configuration.

Note that currently only T2 Macs are supported.

This driver is based on previous work done by Ronald Tschalär
<ronald@innovation.ch>.

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Co-developed-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
 .../ABI/testing/sysfs-driver-hid-appletb-kbd  |  13 +
 drivers/hid/Kconfig                           |  11 +
 drivers/hid/Makefile                          |   1 +
 drivers/hid/hid-appletb-kbd.c                 | 303 ++++++++++++++++++
 drivers/hid/hid-quirks.c                      |   4 +-
 5 files changed, 331 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd
 create mode 100644 drivers/hid/hid-appletb-kbd.c

diff --git a/Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd b/Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd
new file mode 100644
index 000000000..2a19584d0
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd
@@ -0,0 +1,13 @@
+What:		/sys/bus/hid/drivers/hid-appletb-kbd/<dev>/mode
+Date:		September, 2023
+KernelVersion:	6.5
+Contact:	linux-input@vger.kernel.org
+Description:
+		The set of keys displayed on the Touch Bar.
+		Valid values are:
+		== =================
+		0  Escape key only
+		1  Function keys
+		2  Media/brightness keys
+		3  None
+		== =================
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 4988c1fb2..72b665eda 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -158,6 +158,17 @@ config HID_APPLETB_BL
 	  To compile this driver as a module, choose M here: the
 	  module will be called hid-appletb-bl.
 
+config HID_APPLETB_KBD
+	tristate "Apple Touch Bar Keyboard Mode"
+	depends on USB_HID
+	help
+	  Say Y here if you want support for the keyboard mode (escape,
+	  function, media and brightness keys) of Touch Bars on x86 MacBook
+	  Pros.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hid-appletb-kbd.
+
 config HID_ASUS
 	tristate "Asus"
 	depends on USB_HID
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 1d825a474..d903c9a26 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_HID_ACRUX)		+= hid-axff.o
 obj-$(CONFIG_HID_APPLE)		+= hid-apple.o
 obj-$(CONFIG_HID_APPLEIR)	+= hid-appleir.o
 obj-$(CONFIG_HID_APPLETB_BL)	+= hid-appletb-bl.o
+obj-$(CONFIG_HID_APPLETB_KBD)	+= hid-appletb-kbd.o
 obj-$(CONFIG_HID_CREATIVE_SB0540)	+= hid-creative-sb0540.o
 obj-$(CONFIG_HID_ASUS)		+= hid-asus.o
 obj-$(CONFIG_HID_AUREAL)	+= hid-aureal.o
diff --git a/drivers/hid/hid-appletb-kbd.c b/drivers/hid/hid-appletb-kbd.c
new file mode 100644
index 000000000..0b6ac8c59
--- /dev/null
+++ b/drivers/hid/hid-appletb-kbd.c
@@ -0,0 +1,303 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Apple Touch Bar Keyboard Mode Driver
+ *
+ * Copyright (c) 2017-2018 Ronald Tschalär
+ * Copyright (c) 2022-2023 Kerem Karabay <kekrby@gmail.com>
+ * Copyright (c) 2024 Aditya Garg <gargaditya08@live.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/hid.h>
+#include <linux/usb.h>
+#include <linux/input.h>
+#include <linux/sysfs.h>
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/input/sparse-keymap.h>
+
+#include "hid-ids.h"
+
+#define APPLETB_KBD_MODE_ESC	0
+#define APPLETB_KBD_MODE_FN	1
+#define APPLETB_KBD_MODE_SPCL	2
+#define APPLETB_KBD_MODE_OFF	3
+#define APPLETB_KBD_MODE_MAX	APPLETB_KBD_MODE_OFF
+
+#define HID_USAGE_MODE		0x00ff0004
+
+static int appletb_tb_def_mode = APPLETB_KBD_MODE_FN;
+module_param_named(mode, appletb_tb_def_mode, int, 0444);
+MODULE_PARM_DESC(mode, "Default touchbar mode:\n"
+			 "    0 - escape key only\n"
+			 "    [1] - function-keys only\n"
+			 "    2 - special keys only");
+
+struct appletb_kbd {
+	struct hid_field *mode_field;
+
+	u8 saved_mode;
+	u8 current_mode;
+};
+
+static const struct key_entry appletb_kbd_keymap_spcl[] = {
+	{ KE_KEY, KEY_ESC, { KEY_ESC } },
+	{ KE_KEY, KEY_F1,  { KEY_BRIGHTNESSDOWN } },
+	{ KE_KEY, KEY_F2,  { KEY_BRIGHTNESSUP } },
+	{ KE_KEY, KEY_F3,  { KEY_RESERVED } },
+	{ KE_KEY, KEY_F4,  { KEY_RESERVED } },
+	{ KE_KEY, KEY_F5,  { KEY_KBDILLUMDOWN } },
+	{ KE_KEY, KEY_F6,  { KEY_KBDILLUMUP } },
+	{ KE_KEY, KEY_F7,  { KEY_PREVIOUSSONG } },
+	{ KE_KEY, KEY_F8,  { KEY_PLAYPAUSE } },
+	{ KE_KEY, KEY_F9,  { KEY_NEXTSONG } },
+	{ KE_KEY, KEY_F10, { KEY_MUTE } },
+	{ KE_KEY, KEY_F11, { KEY_VOLUMEDOWN } },
+	{ KE_KEY, KEY_F12, { KEY_VOLUMEUP } },
+	{ KE_END, 0 }
+};
+
+static int appletb_kbd_set_mode(struct appletb_kbd *kbd, u8 mode)
+{
+	struct hid_report *report = kbd->mode_field->report;
+	struct hid_device *hdev = report->device;
+	int ret;
+
+	ret = hid_hw_power(hdev, PM_HINT_FULLON);
+	if (ret) {
+		hid_err(hdev, "Device didn't resume (%pe)\n", ERR_PTR(ret));
+		return ret;
+	}
+
+	ret = hid_set_field(kbd->mode_field, 0, mode);
+	if (ret) {
+		hid_err(hdev, "Failed to set mode field to %u (%pe)\n", mode, ERR_PTR(ret));
+		goto power_normal;
+	}
+
+	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
+
+	kbd->current_mode = mode;
+
+power_normal:
+	hid_hw_power(hdev, PM_HINT_NORMAL);
+
+	return ret;
+}
+
+static ssize_t mode_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct appletb_kbd *kbd = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", kbd->current_mode);
+}
+
+static ssize_t mode_store(struct device *dev,
+			  struct device_attribute *attr,
+			  const char *buf, size_t size)
+{
+	struct appletb_kbd *kbd = dev_get_drvdata(dev);
+	u8 mode;
+	int ret;
+
+	ret = kstrtou8(buf, 0, &mode);
+	if (ret)
+		return ret;
+
+	if (mode > APPLETB_KBD_MODE_MAX)
+		return -EINVAL;
+
+	ret = appletb_kbd_set_mode(kbd, mode);
+
+	return ret < 0 ? ret : size;
+}
+static DEVICE_ATTR_RW(mode);
+
+struct attribute *appletb_kbd_attrs[] = {
+	&dev_attr_mode.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(appletb_kbd);
+
+static int appletb_tb_key_to_slot(unsigned int code)
+{
+	switch (code) {
+	case KEY_ESC:
+		return 0;
+	case KEY_F1 ... KEY_F10:
+		return code - KEY_F1 + 1;
+	case KEY_F11 ... KEY_F12:
+		return code - KEY_F11 + 11;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int appletb_kbd_hid_event(struct hid_device *hdev, struct hid_field *field,
+				      struct hid_usage *usage, __s32 value)
+{
+	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
+	struct key_entry *translation;
+	struct input_dev *input;
+	int slot;
+
+	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_KEYBOARD || usage->type != EV_KEY)
+		return 0;
+
+	input = field->hidinput->input;
+
+	/*
+	 * Skip non-touch-bar keys.
+	 *
+	 * Either the touch bar itself or usbhid generate a slew of key-down
+	 * events for all the meta keys. None of which we're at all interested
+	 * in.
+	 */
+	slot = appletb_tb_key_to_slot(usage->code);
+	if (slot < 0)
+		return 0;
+
+	translation = sparse_keymap_entry_from_scancode(input, usage->code);
+
+	if (translation && kbd->current_mode == APPLETB_KBD_MODE_SPCL) {
+		input_event(input, usage->type, translation->keycode, value);
+
+		return 1;
+	}
+
+	return kbd->current_mode == APPLETB_KBD_MODE_OFF;
+}
+
+static int appletb_kbd_input_configured(struct hid_device *hdev, struct hid_input *hidinput)
+{
+	struct input_dev *input = hidinput->input;
+
+	/*
+	 * Clear various input capabilities that are blindly set by the hid
+	 * driver (usbkbd.c)
+	 */
+	memset(input->evbit, 0, sizeof(input->evbit));
+	memset(input->keybit, 0, sizeof(input->keybit));
+	memset(input->ledbit, 0, sizeof(input->ledbit));
+
+	__set_bit(EV_REP, input->evbit);
+
+	sparse_keymap_setup(input, appletb_kbd_keymap_spcl, NULL);
+
+	for (int i = KEY_F1; i <= KEY_F12; i++) {
+		input_set_capability(input, EV_KEY, i);
+	}
+
+	return 0;
+}
+
+static int appletb_kbd_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	struct appletb_kbd *kbd;
+	struct device *dev = &hdev->dev;
+	struct hid_field *mode_field;
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID parse failed\n");
+
+	mode_field = hid_find_field(hdev, HID_OUTPUT_REPORT,
+				    HID_GD_KEYBOARD, HID_USAGE_MODE);
+	if (!mode_field)
+		return -ENODEV;
+
+	kbd = devm_kzalloc(dev, sizeof(*kbd), GFP_KERNEL);
+	if (!kbd)
+		return -ENOMEM;
+
+	kbd->mode_field = mode_field;
+
+	ret = hid_hw_start(hdev, HID_CONNECT_HIDINPUT);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID hw start failed\n");
+
+	ret = hid_hw_open(hdev);
+	if (ret) {
+		dev_err_probe(dev, ret, "HID hw open failed\n");
+		goto stop_hw;
+	}
+
+	ret = appletb_kbd_set_mode(kbd, appletb_tb_def_mode);
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to set touchbar mode\n");
+		goto close_hw;
+	}
+
+	hid_set_drvdata(hdev, kbd);
+
+	return 0;
+
+close_hw:
+	hid_hw_close(hdev);
+stop_hw:
+	hid_hw_stop(hdev);
+	return ret;
+}
+
+static void appletb_kbd_remove(struct hid_device *hdev)
+{
+	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
+
+	appletb_kbd_set_mode(kbd, APPLETB_KBD_MODE_OFF);
+
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
+#ifdef CONFIG_PM
+static int appletb_kbd_suspend(struct hid_device *hdev, pm_message_t msg)
+{
+	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
+
+	kbd->saved_mode = kbd->current_mode;
+	appletb_kbd_set_mode(kbd, APPLETB_KBD_MODE_OFF);
+
+	return 0;
+}
+
+static int appletb_kbd_reset_resume(struct hid_device *hdev)
+{
+	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
+
+	appletb_kbd_set_mode(kbd, kbd->saved_mode);
+
+	return 0;
+}
+#endif
+
+static const struct hid_device_id appletb_kbd_hid_ids[] = {
+	/* MacBook Pro's 2018, 2019, with T2 chip: iBridge Display */
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, appletb_kbd_hid_ids);
+
+static struct hid_driver appletb_kbd_hid_driver = {
+	.name = "hid-appletb-kbd",
+	.id_table = appletb_kbd_hid_ids,
+	.probe = appletb_kbd_probe,
+	.remove = appletb_kbd_remove,
+	.event = appletb_kbd_hid_event,
+	.input_configured = appletb_kbd_input_configured,
+#ifdef CONFIG_PM
+	.suspend = appletb_kbd_suspend,
+	.reset_resume = appletb_kbd_reset_resume,
+#endif
+	.driver.dev_groups = appletb_kbd_groups,
+};
+module_hid_driver(appletb_kbd_hid_driver);
+
+MODULE_AUTHOR("Ronald Tschalär");
+MODULE_AUTHOR("Kerem Karabay <kekrby@gmail.com>");
+MODULE_DESCRIPTION("MacBookPro Touch Bar Keyboard Mode Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c
index 818d41a35..7c576d654 100644
--- a/drivers/hid/hid-quirks.c
+++ b/drivers/hid/hid-quirks.c
@@ -328,7 +328,6 @@ static const struct hid_device_id hid_have_special_driver[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_GEYSER1_TP_ONLY) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_2021) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_FINGERPRINT_2021) },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
 #endif
 #if IS_ENABLED(CONFIG_HID_APPLEIR)
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IRCONTROL) },
@@ -340,6 +339,9 @@ static const struct hid_device_id hid_have_special_driver[] = {
 #if IS_ENABLED(CONFIG_HID_APPLETB_BL)
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
 #endif
+#if IS_ENABLED(CONFIG_HID_APPLETB_KBD)
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
+#endif
 #if IS_ENABLED(CONFIG_HID_ASUS)
 	{ HID_I2C_DEVICE(USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_I2C_KEYBOARD) },
 	{ HID_I2C_DEVICE(USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_I2C_TOUCHPAD) },
-- 
2.39.3 (Apple Git-146)

[PATCH v3 3/9] HID: multitouch: support getting the contact ID from HID_DG_TRANSDUCER_INDEX fields

[Aditya Garg]

From: Kerem Karabay <kekrby@gmail.com>

This is needed to support Apple Touch Bars, where the contact ID is
contained in fields with the HID_DG_TRANSDUCER_INDEX usage.

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
 drivers/hid/hid-multitouch.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 56fc78841..3e92789ed 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -635,7 +635,9 @@ static struct mt_report_data *mt_allocate_report_data(struct mt_device *td,
 
 		if (field->logical == HID_DG_FINGER || td->hdev->group != HID_GROUP_MULTITOUCH_WIN_8) {
 			for (n = 0; n < field->report_count; n++) {
-				if (field->usage[n].hid == HID_DG_CONTACTID) {
+				unsigned int hid = field->usage[n].hid;
+
+				if (hid == HID_DG_CONTACTID || hid == HID_DG_TRANSDUCER_INDEX) {
 					rdata->is_mt_collection = true;
 					break;
 				}
@@ -814,6 +816,7 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 			MT_STORE_FIELD(tip_state);
 			return 1;
 		case HID_DG_CONTACTID:
+		case HID_DG_TRANSDUCER_INDEX:
 			MT_STORE_FIELD(contactid);
 			app->touches_by_report++;
 			return 1;
-- 
2.39.3 (Apple Git-146)

[PATCH v2 4/9] HID: multitouch: support getting the tip state from HID_DG_TOUCH fields

[Aditya Garg]

From: Kerem Karabay <kekrby@gmail.com>

This is necessary on Apple Touch Bars, where the tip state is contained
in fields with the HID_DG_TOUCH usage. This feature is gated by a quirk
in order to prevent breaking other devices, see commit c2ef8f21ea8f
("HID: multitouch: add support for trackpads").

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
 drivers/hid/hid-multitouch.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 3e92789ed..571435da5 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -72,6 +72,7 @@ MODULE_LICENSE("GPL");
 #define MT_QUIRK_FORCE_MULTI_INPUT	BIT(20)
 #define MT_QUIRK_DISABLE_WAKEUP		BIT(21)
 #define MT_QUIRK_ORIENTATION_INVERT	BIT(22)
+#define MT_QUIRK_TOUCH_IS_TIPSTATE	BIT(23)
 
 #define MT_INPUTMODE_TOUCHSCREEN	0x02
 #define MT_INPUTMODE_TOUCHPAD		0x03
@@ -809,6 +810,15 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 
 			MT_STORE_FIELD(confidence_state);
 			return 1;
+		case HID_DG_TOUCH:
+			/*
+			 * Legacy devices use TIPSWITCH and not TOUCH.
+			 * Let's just ignore this field unless the quirk is set.
+			 */
+			if (!(cls->quirks & MT_QUIRK_TOUCH_IS_TIPSTATE))
+				return -1;
+
+			fallthrough;
 		case HID_DG_TIPSWITCH:
 			if (field->application != HID_GD_SYSTEM_MULTIAXIS)
 				input_set_capability(hi->input,
@@ -872,10 +882,6 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 		case HID_DG_CONTACTMAX:
 			/* contact max are global to the report */
 			return -1;
-		case HID_DG_TOUCH:
-			/* Legacy devices use TIPSWITCH and not TOUCH.
-			 * Let's just ignore this field. */
-			return -1;
 		}
 		/* let hid-input decide for the others */
 		return 0;
-- 
2.39.3 (Apple Git-146)

[PATCH v2 5/9] HID: multitouch: take cls->maxcontacts into account for devices without a HID_DG_CONTACTMAX field too

[Aditya Garg]

From: Kerem Karabay <kekrby@gmail.com>

This is needed for Apple Touch Bars, where no HID_DG_CONTACTMAX field is
present and the maximum contact count is greater than the default.

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
 drivers/hid/hid-multitouch.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 571435da5..60b675cd1 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -490,9 +490,6 @@ static void mt_feature_mapping(struct hid_device *hdev,
 		if (!td->maxcontacts &&
 		    field->logical_maximum <= MT_MAX_MAXCONTACT)
 			td->maxcontacts = field->logical_maximum;
-		if (td->mtclass.maxcontacts)
-			/* check if the maxcontacts is given by the class */
-			td->maxcontacts = td->mtclass.maxcontacts;
 
 		break;
 	case HID_DG_BUTTONTYPE:
@@ -1309,6 +1306,10 @@ static int mt_touch_input_configured(struct hid_device *hdev,
 	struct input_dev *input = hi->input;
 	int ret;
 
+	/* check if the maxcontacts is given by the class */
+	if (cls->maxcontacts)
+		td->maxcontacts = cls->maxcontacts;
+
 	if (!td->maxcontacts)
 		td->maxcontacts = MT_DEFAULT_MAXCONTACT;
 
-- 
2.39.3 (Apple Git-146)

[PATCH v2 6/9] HID: multitouch: allow specifying if a device is direct in a class

[Aditya Garg]

From: Kerem Karabay <kekrby@gmail.com>

Currently the driver determines the device type based on the
application, but this value is not reliable on Apple Touch Bars, where
the application is HID_DG_TOUCHPAD even though the devices are direct,
so allow setting it in classes.

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
 drivers/hid/hid-multitouch.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 60b675cd1..2948fbcbc 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -146,6 +146,7 @@ struct mt_class {
 	__s32 sn_height;	/* Signal/noise ratio for height events */
 	__s32 sn_pressure;	/* Signal/noise ratio for pressure events */
 	__u8 maxcontacts;
+	bool is_direct;	/* true for touchscreens */
 	bool is_indirect;	/* true for touchpads */
 	bool export_all_inputs;	/* do not ignore mouse, keyboards, etc... */
 };
@@ -563,13 +564,13 @@ static struct mt_application *mt_allocate_application(struct mt_device *td,
 	mt_application->application = application;
 	INIT_LIST_HEAD(&mt_application->mt_usages);
 
-	if (application == HID_DG_TOUCHSCREEN)
+	if (application == HID_DG_TOUCHSCREEN && !td->mtclass.is_indirect)
 		mt_application->mt_flags |= INPUT_MT_DIRECT;
 
 	/*
 	 * Model touchscreens providing buttons as touchpads.
 	 */
-	if (application == HID_DG_TOUCHPAD) {
+	if (application == HID_DG_TOUCHPAD && !td->mtclass.is_direct) {
 		mt_application->mt_flags |= INPUT_MT_POINTER;
 		td->inputmode_value = MT_INPUTMODE_TOUCHPAD;
 	}
@@ -1317,6 +1318,9 @@ static int mt_touch_input_configured(struct hid_device *hdev,
 	if (td->serial_maybe)
 		mt_post_parse_default_settings(td, app);
 
+	if (cls->is_direct)
+		app->mt_flags |= INPUT_MT_DIRECT;
+
 	if (cls->is_indirect)
 		app->mt_flags |= INPUT_MT_POINTER;
 
-- 
2.39.3 (Apple Git-146)

[PATCH v2 7/9] HID: multitouch: add device ID for Apple Touch Bars

[Aditya Garg]

From: Kerem Karabay <kekrby@gmail.com>

Note that this is device ID is for T2 Macs. Testing on T1 Macs would be
appreciated.

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
 drivers/hid/Kconfig          |  1 +
 drivers/hid/hid-multitouch.c | 26 ++++++++++++++++++++++----
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 72b665eda..35ef5d4ef 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -744,6 +744,7 @@ config HID_MULTITOUCH
 	  Say Y here if you have one of the following devices:
 	  - 3M PCT touch screens
 	  - ActionStar dual touch panels
+	  - Touch Bars on x86 MacBook Pros
 	  - Atmel panels
 	  - Cando dual touch panels
 	  - Chunghwa panels
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 2948fbcbc..0fed95536 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -214,6 +214,7 @@ static void mt_post_parse(struct mt_device *td, struct mt_application *app);
 #define MT_CLS_GOOGLE				0x0111
 #define MT_CLS_RAZER_BLADE_STEALTH		0x0112
 #define MT_CLS_SMART_TECH			0x0113
+#define MT_CLS_APPLE_TOUCHBAR			0x0114
 
 #define MT_DEFAULT_MAXCONTACT	10
 #define MT_MAX_MAXCONTACT	250
@@ -398,6 +399,13 @@ static const struct mt_class mt_classes[] = {
 			MT_QUIRK_CONTACT_CNT_ACCURATE |
 			MT_QUIRK_SEPARATE_APP_REPORT,
 	},
+	{ .name = MT_CLS_APPLE_TOUCHBAR,
+		.quirks = MT_QUIRK_HOVERING |
+			MT_QUIRK_TOUCH_IS_TIPSTATE |
+			MT_QUIRK_SLOT_IS_CONTACTID_MINUS_ONE,
+		.is_direct = true,
+		.maxcontacts = 11,
+	},
 	{ }
 };
 
@@ -1747,6 +1755,15 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 		}
 	}
 
+	ret = hid_parse(hdev);
+	if (ret != 0)
+		return ret;
+
+	if (mtclass->name == MT_CLS_APPLE_TOUCHBAR &&
+	    !hid_find_field(hdev, HID_INPUT_REPORT,
+			    HID_DG_TOUCHPAD, HID_DG_TRANSDUCER_INDEX))
+		return -ENODEV;
+
 	td = devm_kzalloc(&hdev->dev, sizeof(struct mt_device), GFP_KERNEL);
 	if (!td) {
 		dev_err(&hdev->dev, "cannot allocate multitouch data\n");
@@ -1794,10 +1811,6 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 
 	timer_setup(&td->release_timer, mt_expired_timeout, 0);
 
-	ret = hid_parse(hdev);
-	if (ret != 0)
-		return ret;
-
 	if (mtclass->quirks & MT_QUIRK_FIX_CONST_CONTACT_ID)
 		mt_fix_const_fields(hdev, HID_DG_CONTACTID);
 
@@ -2249,6 +2262,11 @@ static const struct hid_device_id mt_devices[] = {
 		MT_USB_DEVICE(USB_VENDOR_ID_XIROKU,
 			USB_DEVICE_ID_XIROKU_CSR2) },
 
+	/* Apple Touch Bars */
+	{ .driver_data = MT_CLS_APPLE_TOUCHBAR,
+		HID_USB_DEVICE(USB_VENDOR_ID_APPLE,
+			       USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
+
 	/* Google MT devices */
 	{ .driver_data = MT_CLS_GOOGLE,
 		HID_DEVICE(HID_BUS_ANY, HID_GROUP_ANY, USB_VENDOR_ID_GOOGLE,
-- 
2.39.3 (Apple Git-146)

Re: [PATCH v2 0/9] Touch Bar support for T2 Macs

[Aditya Garg]

Looks like I messed up the email series, Resending.

Sorry for the trouble

> On 8 Aug 2024, at 5:23 PM, Aditya Garg <gargaditya08@live.com> wrote:
> 
> Hi Maintainers
> 
> The Touch Bars found on x86 Macs support two USB configurations: one
> where the device presents itself as a HID keyboard and can display
> predefined sets of keys, and one where the operating system has full
> control over what is displayed.
> 
> This patch series adds support for both the configurations.
> 
> The hid-appletb-bl driver adds support for the backlight of the Touch Bar.
> This enables the user to control the brightness of the Touch Bar from
> userspace. The Touch Bar supports 3 modes here: Max brightness, Dim and Off.
> So, daemons, used to manage Touch Bar can easily manage these modes by writing
> to /sys/class/backlight/appletb_backlight/brightness. It is needed by both the
> configurations of the Touch Bar.
> 
> The hid-appletb-kbd adds support for the first (predefined keys) configuration.
> There are 4 modes here: Esc key only, Fn mode, Media keys and No keys.
> Mode can be changed by writing to /sys/bus/hid/drivers/hid-appletb-kbd/<dev>/mode
> This configuration is what Windows uses with the official Apple Bootcamp drivers.
> 
> Rest patches support the second configuration, where the OS has full control
> on what's displayed on the Touch Bar. It is achieved by the patching the
> hid-multitouch driver to add support for touch feedback from the Touch Bar
> and the appletbdrm driver, that displays what we want to on the Touch Bar.
> This configuration is what macOS uses.
> 
> The appletbdrm driver is based on the similar driver made for Windows by
> imbushuo [1].
> 
> Currently, a daemon named tiny-dfr [2] is being used to display function keys
> and media controls using the second configuration for both Apple Silicon and
> T2 Macs.
> 
> A daemon for the first configuration is being developed, but that's a userspace
> thing.
> 
> [1]: https://github.com/imbushuo/DFRDisplayKm
> [2]: https://github.com/WhatAmISupposedToPutHere/tiny-dfr
> 
> v2:
>  1. Cleaned up some code in the hid-appletb-kbd driver.
>  2. Fixed wrong subject in drm/format-helper patch.
>  3. Fixed Co-developed-by wrongly added to hid-multitouch patch.
> 
> Kerem Karabay (9):
>  HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars
>  HID: hid-appletb-kbd: add driver for the keyboard mode of Apple Touch
>    Bars
>  HID: multitouch: support getting the contact ID from
>    HID_DG_TRANSDUCER_INDEX fields
>  HID: multitouch: support getting the tip state from HID_DG_TOUCH
>    fields
>  HID: multitouch: take cls->maxcontacts into account for devices
>    without a HID_DG_CONTACTMAX field too
>  HID: multitouch: allow specifying if a device is direct in a class
>  HID: multitouch: add device ID for Apple Touch Bars
>  drm/format-helper: Add conversion from XRGB8888 to BGR888
>  drm/tiny: add driver for Apple Touch Bars in x86 Macs
> 
> .../ABI/testing/sysfs-driver-hid-appletb-kbd  |  13 +
> MAINTAINERS                                   |  12 +
> drivers/gpu/drm/drm_format_helper.c           |  54 ++
> .../gpu/drm/tests/drm_format_helper_test.c    |  81 +++
> drivers/gpu/drm/tiny/Kconfig                  |  12 +
> drivers/gpu/drm/tiny/Makefile                 |   1 +
> drivers/gpu/drm/tiny/appletbdrm.c             | 624 ++++++++++++++++++
> drivers/hid/Kconfig                           |  22 +
> drivers/hid/Makefile                          |   2 +
> drivers/hid/hid-appletb-bl.c                  | 206 ++++++
> drivers/hid/hid-appletb-kbd.c                 | 303 +++++++++
> drivers/hid/hid-multitouch.c                  |  60 +-
> drivers/hid/hid-quirks.c                      |   8 +-
> include/drm/drm_format_helper.h               |   3 +
> 14 files changed, 1385 insertions(+), 16 deletions(-)
> create mode 100644 Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd
> create mode 100644 drivers/gpu/drm/tiny/appletbdrm.c
> create mode 100644 drivers/hid/hid-appletb-bl.c
> create mode 100644 drivers/hid/hid-appletb-kbd.c
> 
> -- 
> 2.39.3 (Apple Git-146)
>